boy am i glad i'm not the only one that had that. does it look something like this...
first, i got a soldering iron and melted it back together then bought some
seal-all and sealed it over as best i could. short of buying a new one aftermarket or not you're looking at at least 80$.
while you're in there make sure the gaskets are clean of debris. for example:
i gave you a nice big picture so you can see the little flakes of rust and paint.
which reminds me, since you have the tank off make sure it is dry and clear of fumes then proceed to sand, scratch or whatever the inside of the neck at the filler cap. this is where all the lovely paint chips originate from.
good luck :hammer: